If you live in the inner-city of Baltimore....unless you live in a building with a armed guard presence, you aren’t secure unless you carry a weapon yourself. All of these urbanized regions in the eastern half of the nation are the same. If you have an active police presence (like NY City), then it makes a difference. But there are dozens of areas which simply can’t protect the residents.
Yes, many parts of Baltimore are quite bad. And Bloomberg acknowledges this. But his solution is is a typically elitist one. Provide protection for upper classes only (in this case, a fancy university).